The present invention relates to a system for visualizing digitalized image data comprising at least one image data source and one image data sink. Additionally, the invention relates to a device for transmitting digitalized image data comprising at least one image data source. Furthermore, the invention relates to a corresponding method for visualizing digitalized image data. Advantageously, the invention relates to a web-based real-time visualization of digitalized image data.
The digitalized image data to be visualized may, for example, come from a microscope coupled to a camera and a corresponding processing unit, for example a computer. In order to take a picture the sample as completely as possible, the sample is mostly moved laterally and also vertically (i.e. in the z direction) relative to the objective of the microscope. Visualization is described, for example, in US 2015/0015578 A1, US 2004/0167806 A1 and DE 699 25 084 T2.
Image data from pictures coming from different lateral regions will subsequently be referred to as field of view. The number of fields of view here depends mainly on the characteristics of the objective of the microscope, the size of the region to be considered and the pixel quantity of the camera. When taking pictures at a lateral position in different z positions, i.e. in different height positions, the term image stack will be used for the entirety of the associated image data. Finally, the entirety of all the fields of view and image stacks will be referred to as a digital slide. As discussed below, this is supplemented by different resolutions.
The term real-time visualization generally describes a display of the image data, continuous or smooth for the observer, without any reloading processes which functionally run in the background being recognizable.
In the application example of digital microscopy, real-time visualization refers to both the zoom process into the image data and also the change of the image displayed from one image stack to another one. This is to resemble “focusing”, like in the microscope.
When there is, for example, a slide having 900 fields of view (including image stacks with 11 levels each), the memory space necessitated will be roughly 30 GB. Such data quantities, however, cannot be visualized in real-time using the Web, so that methods for dealing with such data quantities are known already.
Real-time visualization is dependent on the quantity of the region to be displayed so that displaying the image data in a full-screen mode on a small monitor may be more continuous or smooth than on a large monitor. A further influencing factor is the speed of the internet connection for transmitting the image data via the Web.
In the real-time visualization of large 2D image data in the web browser, there are different requirement categories. When the image is to be displayed without a zoom function, usually subdividing the image into smaller image tiles will be sufficient for a continuous display of an image section. Here, only the respective image tiles necessitated are transmitted.
In the case of a zoom function, the entire image is additionally stored in lower resolutions. However, the data quantity increases by storing the image in several resolution levels.
Special converting methods for reducing the data quantity try to avoid redundant information. The image data in the lower resolution levels, for example, are not stored, but calculated. This may be applied in an advantageous manner when the image contents differ from one another only slightly. Image stacks of very different contents, in contrast, cannot be stored in a considerably more efficient manner.
A large disadvantage of a receiver-side or server-side conversion of large image data is the latency time resulting on the one hand and the necessitated computing power on the other hand.
Dealing with large image data quantities applies not only to the field of digital microscopy, but results, for example, also when dealing with satellite data or hyper-spectrograms. The image data here are usually transmitted from an image data source to an image data sink which form a permanent or, maybe, only temporary system for visualizing image data.
Consequently, the object underlying the invention is suggesting a system for visualizing and a corresponding method which avoid the disadvantages of the known technology and which, above all, allow image stacks to be visualized in the most resource-saving manner and the most continuous manner. In particular, the object refers to 3-dimensional image data having been described before which are associated to several layers in at least partly differing resolutions.